Electromagnetic contactor unit



July 29, 1969 2 Sheets-Sheet l Filed sept. 25, 1967 7 z/, m $19 d ffm July 29, 1969 E. w. ISLE-:R

ELECTROMAGNETIC CONTACTOR UNIT 2 sheets-sheetI a Filed sept. 25,l 1967 United States Patent Office 3,458,838 Patented July 29, 1969 York Filed Sept. 25, 1967, Ser. No. 670,171 Int. Cl. H01h 67/02 U.S. Cl. 335-132 10 Claims ABSTRACT F THE DISCLOSURE A generally rectangular housing is divided centrally into a base portion and .an outer contact portion. A contact carrier is spring mounted within the housing. A movable contact assembly is carried thereby within the contact portion. Additionally, an electromagnetic device is disposed within the base portion and includes a two-part magnet; the one part being the armature connected to the carrier. The other part; the core is held within a coil or Winding by a spring loaded clamp including a spring held latch member removable through an opening in the base. The opening is large enough to allow the movement of the fixed core therethrough. The coil is removable through a side Wall opening such that the coil and armature can be disassembled Without disconnection or disassembly of the total contactor.

The contact carrier is generally an H-shaped member having the armature secured to the underside of the central portion through a releasable tab and recess type connection. The side arms of the carrier provide a guide means for the carrier and in addition provide auxiliary contact actuation through a tab and an opening connection to auxiliary switch contact arms.

The contacts for the coil include contact strips secured exteriorly to the contact housing and extending downwardly through a channel system within the housing and including a contact end immediately adjacent one side of the coil unit. The coil unit in turn has an exposed contact mating with the contact strip in the assembled position.

This invention relates to an electromagnetic contactor unit and particularly to such a contactor forming a part of an alternating current motor starter assembly and the like.

Alternating current motors and the like are interconnected to suitable power lines through special electromagnetic contactors. Auxiliary control contacts are often provided which should be actuated with the main contacts.

Such motor starters have reached a relatively highly developed state of the art as a result of the age of alternating current motors and the continued efforts toward provision of compact units which may be readily and easily serviced. A highly satisfactory unit is shown in applicants copending application entitled, Electrical Contactor, tiled on Oct. 7, 1965 with Ser. No. 493,824, now Patent No. 3,388,353.

The present invention is particularly directed to an mprovement in a similar motor contactor employing a contact assembly .and a movable armature of a magnet interconnected to a single carrier in combination with a `readily removable magnetic actuating coil unit and ixed portion of the core. The coil unit and core can be readily removed exteriorly of the unit without the disassembly of the housing or other associated components and without rst breaking the circuit connections.

Generally, in accordance with the present invention, a two-piece or part housing similar to that of applicants copending application is interconnected through a suitable connection of bolts or the like, which extend through opposite side walls of the units to clamp the actuator housing between the contact housing and a mounting plate-like base or closure member. The magnet unit includes a generally U-shaped core with parallel arms yand a coil unit having openings to receive the arms. The core is inserted into the actuator housing through an opening in the closure member after insertion of the coil unit. A latch unit is inserted through the opening and engages the core to clamp the core and the coil unit within the actuator housing. In one novel embodiment, a latch plate mates with the opening in the base with a spring disposed between the latch member and the base of the U-shaped core. The latch member is then pushed inwardly into .a locking position relative to the base to provide a readily released but reliable clamping of the core and coil unit in place. Thus, the latch member may be a plate slightly smaller than the opening. The plate is forced inwardly twisted to and released to latch the core and coil Within the assembly. interconnecting tab end openings may hold the latch plate against twisting movement after release.

A contact yand armature carrier is slidably mounted within the housing. The carrier is H-shaped with the cross arm generally .aligned with the mating surfaces of the two housing portions. The armature is held within the cross arm in alignment with the fixed core. The side arms of the H-shaped carrier are spring loaded to normally hold the carrier in an outward position with the armature spaced from the iixed core. The side arms of the H-shaped carrier are interconnected to auxiliary switch lever means to actuate the auxiliary switches in response to movement of the armature.

Interconnection to the operating winding of the coil unit is made through a pair of contact strips which extend downwardly through suitable channels in the housing and have a bent portion located to resiliently engage input contacts on the side of the coil unit.

It has been found that this assembly provides a small and compact main contactor while maintaining ready servicing and access to the several components including the auxiliary contacts.

The drawings furnished herewith illustrate preferred embodiments of the present invention clearly disclosing the above advantages and features as well as others which will be clear from the following description.

In the drawings:

FIG. l is a side elevational view of a contactor constructed in accordance with the present invention and with one-half of the unit sectioned to show inner details of construction;

FIG. 2 is a longitudinal section taken generally on line 2-2 of FIG. l;

FIG. 3 is an end view from the right side of FIG. l with parts broken away and sectioned to show details of construction;

FIG. 4 is a fragmentary bottom view of the contactor;

FIG. 5 is a perspective view of a control carrier assembly shown in FIGS. 1 4;

FIG. 6 is a fragmentary view more clearly showing the coil connecting contact strip;

FIG. 7 is a view showing an alternative core clamp assembly; and

FIG. 8 is a perspective view of the clamp elements shown in FIG. 7.

Referring to the drawing, an electromagnetic contactor suitable as a motor starter and constructed in acco-rdance with the present invention is shown including a generally rectangular two-piece housing with an outer contact housing 1 and a magnetic actuator or base housing 2 secured to a mounting plate 3 in stacked relation by a pair of clamping nut and bolt units 4. extending through opposite sides of the two housings. The structure of the housing and the components is symmetrical about a central plane and FIG. 1 includes the upper half of the unit in elevation and the lower halt' in section to more clearly illustrate details of construction.

The illustrated contactor is suitable for energization of a three-phase motor or the like and includes three similar line terminals 5 similarly disposed to the opposite sides of the housing. A movable Contact assembly 6 is slidably mounted within the contact housing 1 and includes bridging contacts 7 spanning the inner ends of the line terminals 5. The movable contact assembly 6 is interconnected to a generally H-shaped carrier by a pair of interconnecting attachment screws or bolts 9. An electromagnetic positioner includes an armature 10 secured to the cross member of the carrier and aligned with a generally stationary U-shaped core 11. A rectangular coil unit 12 includes two windows or openings 13 mating with the arms or legs of the U-shaped core 10. The carrier 7 is spring loaded to normally space the armature 10 from the core 11. When the coil unit 12 is energized, the armature 10 is attracted toward the core 11 and carries the contact ansembly with it to engage the contacts 5 and 7 and complete the line circuit.

More particularly, the actuator housing 2 is generally a hollow rectangular member formed of Bakelite or other suitable insulating material and having outer wall ledges 14 projecting partially inwardly towards each other from the principal side walls, as shown in FIG. 2. The bottom of the housing 2 is open and covered by the mounting plate 3. The opposed ledges 14 underlie the line terminals 5 and provide a stop for the generally H-shaped carrier 8.

The H-shaped carrier 8 includes identical side legs or stems 15, each of which is generally an outwardly opening channel-shaped member terminating in the inner end in a tubular spring guide 16. A U-shaped bolt guide 17 ia integrally formed in the base of each of the channel-shaped members in alignment with guides 16. Bolts of the units 4 extend through suitable openings in the mounting plate 3 and the side legs of the H-shaped carrier 8 including the tubular spring guides 16 and the channel guides 17 and thread into a nut 18 in a recess in the Outer wall of the contact housing 1. A spring 19 encircles the bolt 18 between the mounting plate 3 and the base of the tubular guides 16 and continuously urges the H-shaped carrier 8 from the base plate and towards the contact housing 1. The cross-bar portion of the carrier 8 includes a generally rectangular open frame 20 with the ends of the frame beneath the ledges 14 of the housing 2 to limit the movement of the carrier 8, as shown in FIG. 2.

The rectangular frame 20 supports the armature 10 as follows. As most clearly shown in FIG. 2, an inwardly projecting lip 21 is formed on the one end of the frame 20. The side walls of frame 20 are notched as at 22, as shown in FIG. 1.

The armature 10 is laminated in the shape of a generally rectangular block just slightly smaller than the opening of rectangular frame 20. The opposite ends of the armature 10 are similarly provided with notches 23 on the back side such that the central portion is offset outwardly. L-shaped side plates 24 are Secured to the opposite faces or side walls and define outwardly extending flanges along a substantial central portion of the armature in the outer plane of the armature. In assembly the armature is placed within the frame 20 with the one notch 20 fitting underneath the ledge or lip 21 and the flanges o-f the side plates 24 resting on the adjacent notched side edges 22 of the mounting frame 20.

With the carrier 8 in the outer position, the armature 10 is positively held in position by abutting a central bottom wall 25 of housing 1. When the coil unit 10 is energized, the armature 10 is attracted to core 11 and thus positively held in the frame 20 with flanges of plates 24 bearing on the side edges of the frame.

The base housing 2 is provided with side wall slots or openings 26 in alignment with the legs of the carrier 8. A small outer tab 27 is integrally formed on each carrier leg and is slidably disposed within the corresponding slot 26. In assembly, the armature 10 is placed in frame 20 and the carrier 8 placed in the housing 2 until the tabs 27 engage the bottom edge. The legs of carrier 8 may then be forced inwardly suiciently to move the carrier into the housing 2 until tabs 27 are aligned with slots 26.

The U-shaped core 11 and the coil unit 12 are releasably mounted within the housing 2 to permit assembly and disassembly without removal of any terminal connection, separation of the housings 1 and 2 or the like by the following construction.

The mounting plate 3 is interconnected to the housings 1 and 2 by the attachment nut and bolt units 4. The plate includes a rectangular opening 28 slightly larger than core 11 and generally in alignment with the location of the core 11 and armature 10. The opposite ends of the opening are provided with inwardly projecting tabs 29 having nylon sleeves 30 or the like secured thereon. The U-shaped core 11 is adapted to move through the Opening 28 with the side walls slidably engaging the nylon sleeves.

The illustrated coil unit 12 is adapted to be inserted and removed through a side wall opening 31 in the actuator or base housing 2. As diagrammatically illustrated and similar to that of applicants previously referred to copeuding application, the coil unit 12 is generally a rectangular block member having windings embedded within a plastic mass and having the pair of square windows or openings spaced and shaped in accordance with the legs of the U-shaped core 11. The opening 31 is larger than the basic shape of the coil unit 12 which is provided with an outer enlarged end portion 32 to conform to the housing opening. The length of the coil unit 12 is such that the inner end abuts the opposite end wall of the housing 2 immediately beneath a clamping and locating ledge 33 integrally formed thereon. In assembly, the coil unit 12 is first inserted through the opening 28 such that the windows of the unit are aligned with the linely assembled position of the U-shaped core. The U-shaped core unit is then inserted through the opening in plate 3 with legs passing into the windows of the coil unit 12.

A latch plate 34 just slightly smaller than the rectangular opening in the mounting plate 3 includes a central round depression with a spiral spring 35 secured to its inner face. Small clamping lips 35a may be provided overlying the rst convolution of the spring to lock the spring to the latching plate. In assembly, the latch plate is aligned with the opening 28 in the mounting plate 3 Iand pushed inwardly with the spring 35 bearing on the base of the U-shaped core 11 and compressed until the plate 34 is inwardly of the plate 3 and is then twisted 90 to the position shown in FIG. 4. When released, the spring 35 is held compressed and releasably clamps the core 11 and coil unit 12 within the housing 2 with the clamping ledge 33 and the edge of opening 31 forming a stop for the assembly. The plate 3 is shown provided with a pair of small openings 36 which receive outward struck out locking projections on the latch plate 34 to securely hold the assembly in the housing.

This system is found to provide a very simple and reliable means for firmly fixing the core and coil unit within the housing while permitting ready separate removal of the core and coil as individual items for subsequent maintenance and repair.

The contact housing 1 and the components therein are now described. The housing 1 is also a generally rectangular-shaped hollow member. Housing 1 is divided into three similar adjacent contact chambers `with the corresponding line terminals 5 secured to the opposite sides of each of the chambers. As most clearly shown in FIG. 2, each of the line terminals is generally a U-shaped member 37 secured with the one end of the terminal chamber of housing 1 with the contact end portion extending inwardly immediately adjacent the base of the terminal or contact chamber. The member 37 is secured by a small screw to a clamping contact member 38 which is disposed between the side walls of the terminal chamber.

The inner contact member is generally an L-shaped contact strip secured -between a pair of side insulating plates 39 with small spacing strips 40 disposed within the L-shaped member and between the insulating plates. The chamber side walls include inwardly projecting ridges 41 between the base of member 37 and the adjacent portions of member 38 and the edges of plates 39 such that tightening of the screws securely clamps the line terminals in place.

The movable contact assembly 6 is slidably disposed within the central portion of the contact housing 1 between the line terminals 5 and includes a body 42 which is connected to the cross member of the H-shaped carrier 8 immediately adjacent to the inner surfaces of the side arms by the bolts 9. The body 42 is generally a U-shaped member with the bolts passing through the side walls. Three collar-shaped members 43 are integrally formed between the side walls and spaced in accordance with the chambers of the contact housing. The associated bridging contact 7 extends through the collar and is resiliently held in place by `a coil spring 44 that acts between the back side of the bridging contact and the outer portion of the collar member.

As most clearly shown in FIGS. 3 and 6, a coil unit contact strip 45 is connected to the housings to the opposite end of the line terminals 5 on the side of the housings n alignment with the inner end of coil unit 12, as viewed in FIG. 3. Each of the contact strips 45 is similarly formed and includes a straight elongate strap or body extending through the housings 1 `and 2 between the coil unit 12 and an outer contact recess 46 in the end face of housing 1. The outer exposed end of the contact strip 45 is bent normal to the body and projects through an opening in the inner edge corner of the recess 46 to expose the contact portion. The inner end of the contact strip includes an integral U-shaped portion 47 which opens laterally with one arm extending from an edge of the body and locating an outer longer spring arm 48 engaging the side of coil 12 and particularly an exposed contact 49 thereof.

The actuator housing 2 is provided with a generally rectangular corner chamber or passageway 50 with the body of contact strip 45 extending downwardly immediately adjacent the one side wall, as shown in FIGS. 3 and 6. The opposite inner wall of passageway 50 is provided with a slot 51 immediately adjacent the exterior wall. The U-shaped portion 47 has one leg extending laterally adjacent the slotted wall with the base of the U-shaped portion 47 extending outwardly through the slot and with the spring contact arm bent backwardly and spaced from the slotted wall. With housings 1 and 2 interconnected by nut and bolt units 4, contact strip 45 is cl-amped between a clamping edge of the opening to recess 46 in the contact housing and the base of slot 51. This provides a very convenient means for connecting coil unit in the circuit.

Additionally, as noted in applicants copending application, auxiliary contacts are preferably provided in motor starters and the like. The present invention is particularly adapted to using auxiliary contacts similar to those described therein.

In the illustrated embodiment of the invention, the housings 1 and 2 are provided with auxiliary switch recesses 52 on the opposite side from the contact strips 45. The recesses releasably receive small rectangular switch units 53 similar to those described and thus are only briefly described herein. An actuating lever 54 projects outwardly from the inner end and through openings inmthe back wall of the switch recesses. The back Wall is immediately adjacent to side arms of the H-shaped carrier 8 which has suitable apertures 55 to receive the lever 54.

In the illustrated embodiment of the invention, the metallic locking strips 56 extend through the housing and particularly recesses S2. The one end is bent over the face of housing 1 as at 57 and the opposite end extends through a locking opening in the mounting plate 3 and is held in place -by overlying lips 58. The strip 56 is positioned immediately adjacent the side wall of the switch recesses and includes struck out o1' embossed tubular projections 59 adapted to mate with the L-shaped slots in the side walls of the switches 53, as in applicants previous application to which reference may be made for further detail.

Generally, the assembly of the illustrated embodiment of the invention is as follows. The terminals 5 are interconnected to the contact housing 1. The armature 10 is assembled with the H-shaped carrier 8 which is then assembled with the base housing 2 by bending of the outer ends of the side legs inwardly to move the locking tabs 27 just inwardly of the side wall surfaces of the housing. The carrier is forced inwardly until the locking tabs 27 mate with the openings 26 in the housing side walls. The coil unit contact strips 45 are assembled with the contact housing. The housings 1 and 2 are stacked to the mounting plate 3 and interconnected thereto by the locking nut and bolt units 4 with the coil springs 19 disposed between the mounting plate 3 and the bases of the tubular spring guide 16. The U-shaped portions 47 of strips 45 are assembled in passageways 50 with the outer contact arm 48 disposed inwardly of the side walls during the assembly and properly located to engage the contact 49 on the side portions of the coil unit 12. The movable contact assembly 6 is inserted in the contact housing 1 and interconnected to the carrier 8 by the connecting bolts 9. The coil unit 12 is inserted through the side wall opening 31 after which the U-shaped core 11 is moved inwardly through the opening 28 in the plate 3. The latch plate 34 is aligned with the opening, moved inwardly to compress the spring 34 and twisted 90 and released to dispose spring 35 forcing the core 11 to engage the coil unit 10 and force it into latching engagement with the ledge 33 and the edge of opening 31 to securely hold and lock the unit 10 in position. The auxiliary switches 53 can be inserted into the appropriate recesses at any time.

Whenever the coil unit 12 is energized, the magnetic forces attract the armature 10 to the U-shaped core 11. This results in corresponding movement of the H-shaped carrier 8 and the bridging contacts 7 to move into engagement with the line terminals 5. The auxiliary switches 53 are also operated as a result of the coupling to the side arms of the carrier 8.

If for any reason the servicing of the contacts within the contact housing is required, the movable contact assembly is readily removed by releasing of the interconnecting bolts. This permits ready servicing of the movable contacts and replacement thereof as well as servicing of the xed contact unit without disassembly from the balance of the unit.

If the coil unit 12 requires replacement or service, the unit can be readily serviced by rotation of the latch plate -34 to alignment with the base plate opening 31. This allows sequential removal of the latch plate 34, the U- shaped core 11, and the coil unit 12 in a simple and eicient manner.

An alternative clamp assembly for core 11 and unit 12 is shown in FIGS. 7 and 8. In this embodiment, a at, curved spring 60 spans the back side of a U-shaped core 61 which generally corresponds to core 11. The ends of the spring 60 are bent inwardly into recess 62 in the sides of the core. A mounting plate 63, similar to plate 3, is provided with a core entrance opening 64 having bearing portions 65 on opposite sides of the opening. The bearing portions 65 are small U-shaped formed portions in the plate. A spring clip 66 is in the form of a shallow channel and coacts withr the plate 63 and spring 60 to clamp the core in the assembly. The clamping arm 67 of the clip is provided with lateral bearing ends 68 which pivot in the bearing portions 65. In assembly, the coil unit and core are inserted. The clip is placed with the clamping arm 67 parallel to the plate 63 and between the spring 60 and the plate. The clip 66 is then pivoted slightly more than ninety degrees to place clamping arm 67 in a position approximately normal to the core and compresses the spring to lock the coil unit and core in place.

The present invention thus provides further improvement in the construction and design of contactors for motor starting and the like. The several components are formed in a generally modular type construction, minimizing the trouble and expense of inspection, repair and replacement.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. An electromagnetic circuit controlling apparatus having a compartmented housing assembly including a compartmented contact housing and an actuator housing interconnected in stacked relationship, said contact housing having a plurality of side-by-side terminal chambers with a central opening extending therethrough and with related aligned terminals to opposite sides of said central opening and with a movable contact assembly bridging the terminals, the improvement in the structure for moving said contact assembly comprising,

a contact carrier slidably mounted within said housings and including said contact assembly disposed within the central opening of the contact housing portion and having an armature secured to the central prtion of the carrier,

means in the housings to resiliently hold the carrier biased toward the contact housing,

a coil unit releasably mounted in the actuator housing and being removable through an exterior side wall coil opening, said coil unit having at least one winding opening,

stop means in the actuator housing and engageable with said coil unit to limit movement of the coil unit toward the contact housing,

a core having a leg mating with said opening and disposed in a magnetic circuit with said armature,

a base closure means secured to the actuator housing and having an opening aligned with said core, said opening being suiciently large to permit insertion and removal of the core therethrough, and

a resilient latch means insertable and removable through said opening and engaging said core to resiliently lock the core and coil unit within said actuator housing.

2. The apparatus of claim 1 wherein said closure means is a base plate having an opening slightly larger than said core with integral inwardly extending edge opening tabs, sliding bearing means secured to the tabs to slidably engage the adjacent surfaces of the core, a latch plate slightly smaller than said opening and insertable through the opening, said latch plate being rotated to span the opening, and a spring means disposed between the core and the latch plate to resiliently hold the core and coil unit within said actuator housing.

3. The apparatus of claim 1 wherein said carrier is an H-shaped member having side legs each of which extends into the housings and joined by a central member disposed within the actuator housing, an intermediate wall means secured between the side legs and overlying the central member to limit the movement of the carrier into the contact housing, said central member being a rectangular frame member having a lip on the edge adjacent said intermediate wall means, said armature being a blocklike member disposed within said frame and notched to mate with said lip, and support means on said armature extending laterally over the side walls of the frames adjacent said lip.

4. The apparatus of claim 1 wherein said carried is an H-shaped member having side legs disposed adjacent opposed side walls of said housing and a cross-member to which said armature is connected, said side legs being located generally centrally of the side walls, said housings having auxiliary contact chambers to receive switches having an actuating lever and with a chamber wall located adjacent the side legs, said chamber walls being apertured and said side legs having openings aligned and mating with the auxiliary switch levers.

5. The apparatus of claim 1 wherein said actuator housing includes a stop wall means engaging the face of the coil unit adjacent the contact housing opposite the coil opening, said coil unit spanning the housing between the stop wall means and the edge of the opening to limit the movement toward the contact housing, said coil unit having a pair of winding openings, said core being a U- shaped member with the legs extending through said openings and the core base disposed between the coil unit and the base plate, said latch means urging said core toward the coil unit to resiliently clamp the coil unit against the stop wall means and said edge opening. 6. The apparatus of claim 1 wherein said carrier is an H-shaped member having side legs each of which extends into the housing and a cross member disposed within the actuator housing adjacent the connection to the contact housing lmeans connected to the side legs and slidably supporting the carrier in said housings, said armature being a block-like member secured to the cross member, and resilient means coupled to the housings and carrier and urging the carrier to a Standby position with the armature spaced from said core.

7. The apparatus of claim 6 wherein said side legs are channel-shaped having a U-shaped cross section opening toward a side wall of the housings and having an integral tubular end in the actuator housing, the lbase wall of the channel-shaped legs having a small recess aligned with the opening of the tubular end, a bolt means passing through the housings and said recess and tubular end to interconnect said housing, and springs encircling the bolt means within said tubular ends and between the carrier and the closure means to continuously urge the carrier toward the contact housing.

8. The apparatus of claim 1 wherein said housings are generally rectangular members secured in Astacked abutting relation and having a partial intermediate wall adjacent abutting ends of the housings,

said closure member is a base plate disposed adjacent the outer end of the actuator housing, said carrier is an H-shaped member having side legs slidably disposed adjacent the lside Walls of the housings and having a cross member disposed within the actuator housing adjacent the connection to the contact housmg. bolt means extending through said housing and base plate and through said side legs and interconnnecting said housings and base plate in stacked relation and supporting the carrier for sliding movement,

spring means encircling said bolt means between the carrier and the base plate to resiliently urge the carrier to a standby position with the cross member abutting said intermediate wall,

said armature being a block-like member secured to the cross member,

said actuator housing having at least two spaced stop Wall means engaging the face of the coil unit adjacent the contact housing,

said coil lunit having a pair of winding openings,

said core being a U-shaped member with the legs extending through said openings and the core base disposed between the coil unit and the base plate, and

said latch means acting between said core base and the base plate to resiliently lock the core and coil unit within said actuator housing.

9. The apparatus of claim 8 wherein said carrier ncludes an outwardly projecting guide tab on each of the side legs, said actuator housing having guide slots centrally of the side walls in alignment with said tabs, said carrier and housing being formed of material having a substantially rigid material having a degree of flexibility sucient to permit insertion and removal of the carrier into said actuator housing by relative lateral deformation of the side legs of the carrier and side Walls of the housing.

10. The apparatus of claim 1 wherein said coil unit includes a pair of exposed coil contacts, and having a pair of exposed coil contacts, and having a pair of contact 10 strips secured to the contact housing and projecting inwardly through said housings with the inner end terminating in spring contacts slidably engaging said exposed coil contacts.

References Cited UNITED STATES PATENTS 3,238,329 3/1966 Russo 335--132 3,251,964 5/1966 Lawrence et a1 335-132 3,324,431 6/1967 Cataldo et a1. S35-132 BERNARD A. GILHEANY, Primary Examiner HAROLD BROOME, Assistant Examiner 

